To better understand how is the ITTF Organisational Structure, please read the document linked here.
On it, you can find the ITTF Structure explained easily, with references to our Constitution and the current composition of our Legislative Authorities (AGM and BoD), the Executive Committee, the Continental Council, the Athletes Commission, Professional Staff, Committees and the Commissioners.
For clarity, you can see also the relations with World Table Tennis and the ITTF Foundation.